题目描述

blablabla

样例

blablabla

算法1

(暴力枚举) $O(n^2)$

blablabla

时间复杂度

参考文献

C++ 代码

#include<iostream>

using namespace std;

const int N = 100010;

int h[N], n;

bool check(int e)
{
    for (int i = 1; i <= n; i ++)
    {
        e = 2 * e - h[i];
        if (e < 0) return false;
        if (e > N) return true;
    }  
    return true;
}

int main()
{
    cin >> n;
    for (int i = 1; i <= n; i ++) cin >> h[i];

    int l = h[0] / 2 + 1, r = 100000;

    while(l < r)
    {
        int mid = l + r >> 1;
        if (check(mid)) r = mid;
        else l = mid + 1;
    }
    cout << r;
    return 0;
}

算法2

(暴力枚举) $O(n^2)$

blablabla

时间复杂度

参考文献

C++ 代码

//贪心；
#include<iostream>

using namespace std;

const int N = 100010;

int h[N], n;



int main()
{
    cin >> n;
    for (int i = 1; i <= n; i ++) cin >> h[i];
    int res = 0;
    for (int i = n; i >= 1; i --)
    {
        res = (res + h[i] + 1) / 2;
    }
    cout << res;
    return 0;
}